Georgia is taking its get-tough-on-crime efforts to a new and controversial level by moving toward the abolishment of an American criminal justice tradition: parole.

To advocates of a constitutional amendment now before the Georgia General Assembly, the issue is simple. Prisoners who are sentenced to 30 years should serve 30 years. The penal system has become too lenient, they say, allowing crooks to return to the streets long before serving out their punishment.

Georgia's move fits into a pattern of state efforts to reduce crime and emphasize punishment over rehabilitation.

New York and Texas, for example, are looking at dismantling their parole boards or making violent offenders ineligible for parole. Many more states now have mandatory sentencing or truth-in-sentencing laws that reduce a judge's discretion in deciding how much time a criminal should spend behind bars. Minnesota lawmakers are discussing whether to give prisoners more time - after they have served their full sentences without parole - if they misbehave in prison.

But critics of Georgia's effort say that by eliminating parole, prisons will become even more overcrowded and taxpayers will have to pay for new prisons.

And historically, parole has worked as the rare carrot in a system based on sticks, parole advocates say.

Typically, a judge sentenced an offender to a range, from 20 to 40 years, for example, understanding that if the offender served 20 years justice would have been carried out. The extra 20 years in the sentence was to encourage an offender to behave, to take part in rehabilitative programs, and to follow the straight and narrow once released. But over time, that system has been misconstrued so that a prisoner sentenced to 20 to 40 years who only serves 20 years is often said to have served only half of his sentence.

"It often gets described as early release, but there's nothing early about it," says Marc Mauer, director of the Sentencing Project in Washington. "People say [later] he only served 50 percent of his sentence, [but] on the day he was sentenced everybody knew that was what he was going to serve."

What has driven the changes to the system, experts say, are highly publicized examples of offenders who commit brutal crimes while out on parole. But to Eric Lotke of the National Center on Institutions and Alternatives in Washington, responding to those incidents by doing away with parole is wrong-headed. Without parole, offenders who have been locked up return to the street with little or no intervening supervision. There, he says, they are more likely to reoffend than if they were under parole.

'The absence of supervision really invites more crime but it's not as politically troublesome because it seems like the person is responsible, not a state agency," he says.

Yet, one reason for the country's large decline in crime in recent years, criminologists say, is that violent criminals are going to prison for longer periods. And research shows that most crimes are committed by a small group of offenders.

"Whether parole serves a function for the prisoner or not, if my principal objective is protection of person and property," argues Mr. Bowers, there can't be any alternative to keeping people in prison longer to reduce crime on the streets."

The parole debate in Georgia is just getting started. Both chambers of the legislature have passed a law abolishing parole from the state constitution. If they can agree on a version, voters will get an opportunity to reject or approve the change this fall.